Any of the basic mechanical devices for applying a force, such as an inclined plane, wedge, or lever.
Answer:
Explanation:
1. New substances such as carbondioxide and water is formed.
2. There is evolution of gas bubbles. Gases are released.
3. There is either the absorption of energy or release of energy in form of light and energy.
4. The reaction is irreversible i.e it cannot be reversed, it is permanent once the reaction take place.
5. There is a change in both odor and smell.
A chemical change is a change where new substances are formed due to changes in the properties.
Answer:
1.12M
Explanation:
Given parameters:
Volume of solution = 2.5L
Mass of Calcium phosphate = 600g
Unknown:
Concentration = ?
Solution:
Concentration is the number of moles of solute in a particular solution.
Now, we find the number of moles of the calcium phosphate from the given mass;
Formula of calcium phosphate = Ca₃PO₄
molar mass = 3(40) + 31 + 4(16) = 215g/mol
Number of moles of Ca₃PO₄ =
= 2.79moles
Now;
Concentration =
Concentration =
= 1.12M
Answer: A. Limestone rocks dissolving in water
Explanation:
B: This is a physical change; it changes an object physically rather than chemically. It does not change the composition of the concrete, only the shape.
C: This is also a physical change because the water is just dragging sand with it, but not actually changing the composition of it.
D: Similar to option B, this is an example of physical weathering because the ice only divides the rock into different parts but doesn't change the composition or complexity of it.
Answer:
295.7 mL of 24% trichloroacetic acid (tca) is needed .
Explanation:
Let the volume of 24% trichloroacetic acid solution be x
Volume of required 10% trichloroacetic acid solution =8 bottles of 3 ounces
= 24 ounces = 709.68 mL
(1 ounces = 29.57 mL)
Amount of trichloroacetic acid in 24% solution of x volume of solution will be equal to amount of trichloroacetic acid in 10% solution of volume 709.68 mL.

x = 295.7 mL
295.7 mL of 24% trichloroacetic acid (tca) is needed .